The “ef-” prefix and de qwawifier “edyw” in “edyw awcohow” originawwy come from de name “edyw” assigned in 1834 to de group C2H5− by Justus Liebig. He coined de word from de German name Aeder of de compound C2H5−O−C2H5 (commonwy cawwed “eder” in Engwish, more specificawwy cawwed “diedyw eder”).[7] According to de Oxford Engwish Dictionary, Edyw is a contraction of de Ancient Greek αἰθήρ (aifḗr, “upper air”) and de Greek word ὕλη (hýwē, “substance”).[8]

The name edanow was coined as a resuwt of a resowution dat was adopted at de Internationaw Conference on Chemicaw Nomencwature dat was hewd in Apriw 1892 in Geneva, Switzerwand.[9]

The term “awcohow” now refers to a wider cwass of substances in chemistry nomencwature, but in common parwance it remains de name of edanow. The Oxford Engwish Dictionary cwaims dat it is a medievaw woan from Arabicaw-kuḥw, a powdered ore of antimony used since antiqwity as a cosmetic, and retained dat meaning in Middwe Latin.[10] The use of “awcohow” for edanow (in fuww, “awcohow of wine”) is modern, first recorded 1753, and by de water 17f century referred to “any subwimated substance; distiwwed spirit” use for “de spirit of wine” (shortened from a fuww expression awcohow of wine). The systematic use in chemistry dates to 1850.

Edanow is used in medicaw wipes and most common antibacteriaw hand sanitizer gews as an antiseptic. Edanow kiwws organisms by denaturing deir proteins and dissowving deir wipids and is effective against most bacteria and fungi, and many viruses. However, edanow is ineffective against bacteriaw spores.[11] 70% edanow is de most effective concentration, particuwarwy because of osmotic pressure. Absowute edanow may inactivate microbes widout destroying dem because de awcohow is unabwe to fuwwy permeate de microbe's membrane.[12][13]

Edyw Awcohow is extensivewy metabowized by de wiver, particuwarwy via de enzyme CYP450.[18] Edyw Awcohow increases de secretion of acids in de stomach.[18] The metabowite acetawdehyde is responsibwe for much of de short term, and wong term effects of edyw awcohow toxicity.[19]

The wargest singwe use of edanow is as an engine fuew and fuew additive. Braziw in particuwar rewies heaviwy upon de use of edanow as an engine fuew, due in part to its rowe as de gwobe's weading producer of edanow.[25]Gasowine sowd in Braziw contains at weast 25% anhydrous edanow. Hydrous edanow (about 95% edanow and 5% water) can be used as fuew in more dan 90% of new gasowine fuewed cars sowd in de country. Braziwian edanow is produced from sugar cane and noted for high carbon seqwestration.[26] The US and many oder countries primariwy use E10 (10% edanow, sometimes known as gasohow) and E85 (85% edanow) edanow/gasowine mixtures.

Austrawian waw wimits de use of pure edanow from sugarcane waste to 10% in automobiwes. Owder cars (and vintage cars designed to use a swower burning fuew) shouwd have de engine vawves upgraded or repwaced.[28]

Edanow combustion in an internaw combustion engine yiewds many of de products of incompwete combustion produced by gasowine and significantwy warger amounts of formawdehyde and rewated species such as acetawdehyde.[31] This weads to a significantwy warger photochemicaw reactivity and more ground wevew ozone.[32] These data have been assembwed into The Cwean Fuews Report comparison of fuew emissions[33] and show dat edanow exhaust generates 2.14 times as much ozone as gasowine exhaust.[34] When dis is added into de custom Locawised Powwution Index (LPI) of The Cwean Fuews Report, de wocaw powwution of edanow (powwution dat contributes to smog) is rated 1.7, where gasowine is 1.0 and higher numbers signify greater powwution, uh-hah-hah-hah.[35] The Cawifornia Air Resources Board formawized dis issue in 2008 by recognizing controw standards for formawdehydes as an emissions controw group, much wike de conventionaw NOx and Reactive Organic Gases (ROGs).[36]

Worwd production of edanow in 2006 was 51 gigawitres (1.3×1010 US gaw), wif 69% of de worwd suppwy coming from Braziw and de United States.[37] More dan 20% of Braziwian cars are abwe to use 100% edanow as fuew, which incwudes edanow-onwy engines and fwex-fuew engines.[38] Fwex-fuew engines in Braziw are abwe to work wif aww edanow, aww gasowine or any mixture of bof. In de US fwex-fuew vehicwes can run on 0% to 85% edanow (15% gasowine) since higher edanow bwends are not yet awwowed or efficient. Braziw supports dis popuwation of edanow-burning automobiwes wif warge nationaw infrastructure dat produces edanow from domesticawwy grown sugar cane. Sugar cane not onwy has a greater concentration of sucrose dan corn (by about 30%), but is awso much easier to extract. The bagasse generated by de process is not wasted, but is used in power pwants to produce ewectricity.[citation needed]

In de United States, de edanow fuew industry is based wargewy on corn. According to de Renewabwe Fuews Association, as of 30 October 2007, 131 grain edanow bio-refineries in de United States have de capacity to produce 7.0 biwwion US gawwons (26,000,000 m3) of edanow per year. An additionaw 72 construction projects underway (in de U.S.) can add 6.4 biwwion US gawwons (24,000,000 m3) of new capacity in de next 18 monds. Over time, it is bewieved dat a materiaw portion of de ≈150-biwwion-US-gawwon (570,000,000 m3) per year market for gasowine wiww begin to be repwaced wif fuew edanow.[39]

Sweet sorghum is anoder potentiaw source of edanow, and is suitabwe for growing in drywand conditions. The Internationaw Crops Research Institute for de Semi-Arid Tropics (ICRISAT) is investigating de possibiwity of growing sorgham as a source of fuew, food, and animaw feed in arid parts of Asia and Africa.[40]Sweet sorghum has one-dird de water reqwirement of sugarcane over de same time period. It awso reqwires about 22% wess water dan corn (awso known as maize). The worwd’s first sweet sorghum edanow distiwwery began commerciaw production in 2007 in Andhra Pradesh, India.[41]

Edanow's high miscibiwity wif water makes it unsuitabwe for shipping drough modern pipewines wike wiqwid hydrocarbons.[42] Mechanics have seen increased cases of damage to smaww engines (in particuwar, de carburetor) and attribute de damage to de increased water retention by edanow in fuew.[43]

Edanow was commonwy used as fuew in earwy bipropewwantrocket (wiqwid propewwed) vehicwes, in conjunction wif an oxidizer such as wiqwid oxygen, uh-hah-hah-hah. The German V-2 rocket of Worwd War II, credited wif beginning de space age, used edanow, mixed wif 25% of water to reduce de combustion chamber temperature.[44][45] The V-2's design team hewped devewop U.S. rockets fowwowing Worwd War II, incwuding de edanow-fuewed Redstone rocket which waunched de first U.S. satewwite.[46] Awcohows feww into generaw disuse as more efficient rocket fuews were devewoped.[45]

Commerciaw fuew cewws operate on reformed naturaw gas, hydrogen or medanow. Edanow is an attractive awternative due to its wide avaiwabiwity, wow cost, high purity and wow toxicity. There are a wide range of fuew ceww concepts dat have been triawwed incwuding direct-edanow fuew cewws, auto-dermaw reforming systems and dermawwy integrated systems. The majority of work is being conducted at a research wevew awdough dere are a number of organizations at de beginning of commerciawization of edanow fuew cewws.[47]

Edanow is miscibwe wif water and is a good generaw purpose sowvent. It is found in paints, tinctures, markers, and personaw care products such as moudwashes, perfumes and deodorants. However, powysaccharidesprecipitate from aqweous sowution in de presence of awcohow, and edanow precipitation is used for dis reason in de purification of DNA and RNA.

Because of its wow mewting point (−114.14 °C) and wow toxicity, edanow is sometimes used in waboratories (wif dry ice or oder coowants) as a coowing baf to keep vessews at temperatures bewow de freezing point of water. For de same reason, it is awso used as de active fwuid in awcohow dermometers.

Edanow is a 2-carbon awcohow. Its mowecuwar formuwa is CH3CH2OH. An awternative notation is CH3−CH2−OH, which indicates dat de carbon of a medyw group (CH3−) is attached to de carbon of a medywene group (−CH2–), which is attached to de oxygen of a hydroxyw group (−OH). It is a constitutionaw isomer of dimedyw eder. Edanow is sometimes abbreviated as EtOH, using de common organic chemistry notation of representing de edyw group (C2H5−) wif Et.

Edanow is a vowatiwe, coworwess wiqwid dat has a swight odor. It burns wif a smokewess bwue fwame dat is not awways visibwe in normaw wight. The physicaw properties of edanow stem primariwy from de presence of its hydroxyw group and de shortness of its carbon chain, uh-hah-hah-hah. Edanow's hydroxyw group is abwe to participate in hydrogen bonding, rendering it more viscous and wess vowatiwe dan wess powar organic compounds of simiwar mowecuwar weight, such as propane.

Edanow is swightwy more refractive dan water, having a refractive index of 1.36242 (at λ=589.3 nm and 18.35 °C or 65.03 °F).[49] The tripwe point for edanow is 150 K at a pressure of 4.3 × 10−4Pa.[50]

Edanow's miscibiwity wif water contrasts wif de immiscibiwity of wonger-chain awcohows (five or more carbon atoms), whose water miscibiwity decreases sharpwy as de number of carbons increases.[52] The miscibiwity of edanow wif awkanes is wimited to awkanes up to undecane: mixtures wif dodecane and higher awkanes show a miscibiwity gap bewow a certain temperature (about 13 °C for dodecane[53]). The miscibiwity gap tends to get wider wif higher awkanes and de temperature for compwete miscibiwity increases.

Edanow-water mixtures have wess vowume dan de sum of deir individuaw components at de given fractions. Mixing eqwaw vowumes of edanow and water resuwts in onwy 1.92 vowumes of mixture.[49][54] Mixing edanow and water is exodermic, wif up to 777 J/mow[55] being reweased at 298 K.

Mixtures of edanow and water form an azeotrope at about 89 mowe-% edanow and 11 mowe-% water[56] or a mixture of 95.6 percent edanow by mass (or about 97% awcohow by vowume) at normaw pressure, which boiws at 351K (78 °C). This azeotropic composition is strongwy temperature- and pressure-dependent and vanishes at temperatures bewow 303 K.[57]

The addition of even a few percent of edanow to water sharpwy reduces de surface tension of water. This property partiawwy expwains de "tears of wine" phenomenon, uh-hah-hah-hah. When wine is swirwed in a gwass, edanow evaporates qwickwy from de din fiwm of wine on de waww of de gwass. As de wine's edanow content decreases, its surface tension increases and de din fiwm "beads up" and runs down de gwass in channews rader dan as a smoof sheet.

An edanow-water sowution dat contains 40% awcohow by weight (about 56% by vowume) wiww catch fire if heated to about 26 °C (79 °F) and if an ignition source is appwied to it. This is cawwed its fwash point.[59] The fwash point of pure edanow is 16.60 °C (61.88 °F), wess dan average room temperature.

Edanow is a byproduct of de metabowic process of yeast. As such, edanow wiww be present in any yeast habitat. Edanow can commonwy be found in overripe fruit.[61] Edanow produced by symbiotic yeast can be found in bertam pawm bwossoms. Awdough some animaw species such as de pentaiwed treeshrew exhibit edanow-seeking behaviors, most show no interest or avoidance of food sources containing edanow.[62] Edanow is awso produced during de germination of many pwants as a resuwt of naturaw anerobiosis.[63] Edanow has been detected in outer space, forming an icy coating around dust grains in interstewwar cwouds.[64] Minute qwantity amounts (average 196 ppb) of endogenous edanow and acetawdehyde were found in de exhawed breaf of heawdy vowunteers.[65]Auto-brewery syndrome, awso known as gut fermentation syndrome, is a rare medicaw condition in which intoxicating qwantities of edanow are produced drough endogenousfermentation widin de digestive system.[66]

Edanow is produced bof as a petrochemicaw, drough de hydration of edywene and, via biowogicaw processes, by fermenting sugars wif yeast.[67] Which process is more economicaw depends on prevaiwing prices of petroweum and grain feed stocks. In de 1970s most industriaw edanow in de United States was made as a petrochemicaw, but in de 1980s de United States introduced subsidies for corn based edanow and today it is awmost aww made from dat source.[68]

In an owder process, first practiced on de industriaw scawe in 1930 by Union Carbide,[74] but now awmost entirewy obsowete, edywene was hydrated indirectwy by reacting it wif concentrated suwfuric acid to produce edyw suwfate, which was hydrowyzed to yiewd edanow and regenerate de suwfuric acid:[75]

Fermentation is de process of cuwturing yeast under favorabwe dermaw conditions to produce awcohow. This process is carried out at around 35–40 °C (95–104 °F). Toxicity of edanow to yeast wimits de edanow concentration obtainabwe by brewing; higher concentrations, derefore, are obtained by fortification or distiwwation. The most edanow-towerant yeast strains can survive up to approximatewy 18% edanow by vowume.

To produce edanow from starchy materiaws such as cereaw grains, de starch must first be converted into sugars. In brewing beer, dis has traditionawwy been accompwished by awwowing de grain to germinate, or mawt, which produces de enzymeamywase. When de mawted grain is mashed, de amywase converts de remaining starches into sugars.

Breweries and biofuew pwants empwoy two medods for measuring edanow concentration, uh-hah-hah-hah. Infrared edanow sensors measure de vibrationaw freqwency of dissowved edanow using de CH band at 2900 cm−1. This medod uses a rewativewy inexpensive sowid state sensor dat compares de CH band wif a reference band to cawcuwate de edanow content. The cawcuwation makes use of de Beer-Lambert waw. Awternativewy, by measuring de density of de starting materiaw and de density of de product, using a hydrometer, de change in specific gravity during fermentation indicates de awcohow content. This inexpensive and indirect medod has a wong history in de beer brewing industry.

Edywene hydration or brewing produces an edanow–water mixture. For most industriaw and fuew uses, de edanow must be purified. Fractionaw distiwwation at atmospheric pressure can concentrate edanow to 95.6% by weight (89.5 mowe%). This mixture is an azeotrope wif a boiwing point of 78.1 °C (172.6 °F), and cannot be furder purified by distiwwation, uh-hah-hah-hah. Addition of an entraining agent, such as benzene, cycwohexane, or heptane, awwows a new ternary azeotrope comprising de edanow, water, and de entraining agent to be formed. This wower-boiwing ternary azeotrope is removed preferentiawwy, weading to water-free edanow.[70]

At pressures wess dan atmospheric pressure, de composition of de edanow-water azeotrope shifts to more edanow-rich mixtures, and at pressures wess dan 70 torr (9.333 kPa), dere is no azeotrope, and it is possibwe to distiww absowute edanow from an edanow-water mixture. Whiwe vacuum distiwwation of edanow is not presentwy economicaw, pressure-swing distiwwation is a topic of current research. In dis techniqwe, a reduced-pressure distiwwation first yiewds an edanow-water mixture of more dan 95.6% edanow. Then, fractionaw distiwwation of dis mixture at atmospheric pressure distiwws off de 95.6% azeotrope, weaving anhydrous edanow at de bottom.[citation needed]

Apart from distiwwation, edanow may be dried by addition of a desiccant, such as mowecuwar sieves, cewwuwose, and cornmeaw. The desiccants can be dried and reused.[70]Mowecuwar sieves can be used to sewectivewy absorb de water from de 95.6% edanow sowution, uh-hah-hah-hah.[82] Syndetic zeowite in pewwet form can be used, as weww as a variety of pwant-derived absorbents, incwuding cornmeaw, straw, and sawdust. The zeowite bed can be regenerated essentiawwy an unwimited number of times by drying it wif a bwast of hot carbon dioxide. Cornmeaw and oder pwant-derived absorbents cannot readiwy be regenerated, but where edanow is made from grain, dey are often avaiwabwe at wow cost. Absowute edanow produced dis way has no residuaw benzene, and can be used to fortify port and sherry in traditionaw winery operations.

Membranes can awso be used to separate edanow and water. Membrane-based separations are not subject to de wimitations of de water-edanow azeotrope because de separations are not based on vapor-wiqwid eqwiwibria. Membranes are often used in de so-cawwed hybrid membrane distiwwation process. This process uses a pre-concentration distiwwation cowumn as first separating step. The furder separation is den accompwished wif a membrane operated eider in vapor permeation or pervaporation mode. Vapor permeation uses a vapor membrane feed and pervaporation uses a wiqwid membrane feed.

A variety of oder techniqwes have been discussed, incwuding de fowwowing:[70]

Sawting using potassium carbonate to expwoit its insowubiwity wiww cause a phase separation wif edanow and water. This offers a very smaww potassium carbonate impurity to de awcohow dat can be removed by distiwwation, uh-hah-hah-hah. This medod is very usefuw in purification of edanow by distiwwation, as edanow forms an azeotrope wif water.

Pure edanow and awcohowic beverages are heaviwy taxed as psychoactive drugs, but edanow has many uses dat do not invowve its consumption, uh-hah-hah-hah. To rewieve de tax burden on dese uses, most jurisdictions waive de tax when an agent has been added to de edanow to render it unfit to drink. These incwude bittering agents such as denatonium benzoate and toxins such as medanow, naphda, and pyridine. Products of dis kind are cawwed denatured awcohow.[85][86]

Absowute or anhydrous awcohow refers to edanow wif a wow water content. There are various grades wif maximum water contents ranging from 1% to a few parts per miwwion (ppm) wevews. If azeotropic distiwwation is used to remove water, it wiww contain trace amounts of de materiaw separation agent (e.g. benzene).[87] Absowute awcohow is not intended for human consumption, uh-hah-hah-hah. Absowute edanow is used as a sowvent for waboratory and industriaw appwications, where water wiww react wif oder chemicaws, and as fuew awcohow. Spectroscopic edanow is an absowute edanow wif a wow absorbance in uwtraviowet and visibwe wight, fit for use as a sowvent in uwtraviowet-visibwe spectroscopy.[88]

Pure edanow is cwassed as 200 proof in de U.S., eqwivawent to 175 degrees proof in de UK system.[89]

Rectified spirit, an azeotropic composition of 96% edanow containing 4% water, is used instead of anhydrous edanow for various purposes. Wine spirits are about 94% edanow (188 proof). The impurities are different from dose in 95% (190 proof) waboratory edanow.[90]

Edanow is cwassified as a primary awcohow, meaning dat de carbon its hydroxyw group attaches to has at weast two hydrogen atoms attached to it as weww. Many edanow reactions occur at its hydroxyw group.

This reaction, which is conducted on warge scawe industriawwy, reqwires de removaw of de water from de reaction mixture as it is formed. Esters react in de presence of an acid or base to give back de awcohow and a sawt. This reaction is known as saponification because it is used in de preparation of soap. Edanow can awso form esters wif inorganic acids. Diedyw suwfate and triedyw phosphate are prepared by treating edanow wif suwfur trioxide and phosphorus pentoxide respectivewy. Diedyw suwfate is a usefuw edywating agent in organic syndesis. Edyw nitrite, prepared from de reaction of edanow wif sodium nitrite and suwfuric acid, was formerwy used as a diuretic.

Strong acid desiccants cause de partiaw dehydration of edanow to form diedyw eder and oder byproducts. If de dehydration temperature exceeds around 160 °C (320 °F), fuww dehydration wiww occur and edywene wiww be de main product.

Edanow is a neutraw mowecuwe and de pH of a sowution of edanow in water is nearwy 7.00. Edanow can be qwantitativewy converted to its conjugate base, de edoxide ion (CH3CH2O−), by reaction wif an awkawi metaw such as sodium:[52]

Edanow can be oxidized to acetawdehyde and furder oxidized to acetic acid, depending on de reagents and conditions.[75] This oxidation is of no importance industriawwy, but in de human body, dese oxidation reactions are catawyzed by de enzymewiver awcohow dehydrogenase. The oxidation product of edanow, acetic acid, is a nutrient for humans, being a precursor to acetyw CoA, where de acetyw group can be spent as energy or used for biosyndesis.

Pure edanow wiww irritate de skin and eyes.[95] Nausea, vomiting, and intoxication are symptoms of ingestion, uh-hah-hah-hah. Long-term use by ingestion can resuwt in serious wiver damage.[96] Atmospheric concentrations above one in a dousand are above de European Union occupationaw exposure wimits.[96]

The fermentation of sugar into edanow is one of de earwiest biotechnowogies empwoyed by humans. The intoxicating effects of edanow consumption have been known since ancient times. Edanow has been used by humans since prehistory as de intoxicating ingredient of awcohowic beverages. Dried residue on 9,000-year-owd pottery found in China suggests dat Neowidic peopwe consumed awcohowic beverages.[97]

In China, archaeowogicaw evidence indicates dat de true distiwwation of awcohow began during de 12f century Jin or Soudern Song dynasties.[103] A stiww has been found at an archaeowogicaw site in Qingwong, Hebei, dating to de 12f century.[103] In India, de true distiwwation of awcohow was introduced from de Middwe East, and was in wide use in de Dewhi Suwtanate by de 14f century.[101]

In 1796, German-Russian chemist Johann Tobias Lowitz obtained pure edanow by mixing partiawwy purified edanow (de awcohow-water azeotrope) wif an excess of anhydrous awkawi and den distiwwing de mixture over wow heat.[104] French chemist Antoine Lavoisier described edanow as a compound of carbon, hydrogen, and oxygen, and in 1807 Nicowas-Théodore de Saussure determined edanow's chemicaw formuwa.[105][106] Fifty years water, Archibawd Scott Couper pubwished de structuraw formuwa of edanow. It was one of de first structuraw formuwas determined.[107]

Edanow was first prepared syndeticawwy in 1825 by Michaew Faraday. He found dat suwfuric acid couwd absorb warge vowumes of coaw gas.[108] He gave de resuwting sowution to Henry Henneww, a British chemist, who found in 1826 dat it contained "suwphovinic acid" (edyw hydrogen suwfate).[109] In 1828, Henneww and de French chemist Georges-Simon Seruwwas independentwy discovered dat suwphovinic acid couwd be decomposed into edanow.[110][111] Thus, in 1825 Faraday had unwittingwy discovered dat edanow couwd be produced from edywene (a component of coaw gas) by acid-catawyzed hydration, a process simiwar to current industriaw edanow syndesis.[112]

Edanow was used as wamp fuew in de United States as earwy as 1840, but a tax wevied on industriaw awcohow during de Civiw War made dis use uneconomicaw. The tax was repeawed in 1906.[113] Use as an automotive fuew dates back to 1908, wif de Ford Modew T abwe to run on petrow (gasowine) or edanow.[114] It fuews some spirit wamps.

Edanow intended for industriaw use is often produced from edywene.[115] Edanow has widespread use as a sowvent of substances intended for human contact or consumption, incwuding scents, fwavorings, coworings, and medicines. In chemistry, it is bof a sowvent and a feedstock for de syndesis of oder products. It has a wong history as a fuew for heat and wight, and more recentwy as a fuew for internaw combustion engines.

Armstrong's report is reprinted wif de resowutions in Engwish in: Armstrong H (1892). "The Internationaw Conference on Chemicaw Nomencwature". The Journaw of Anawyticaw and Appwied Chemistry. 6: 390–400 (398). The awcohows and de phenows wiww be cawwed after de name of de hydrocarbon from which dey are derived, terminated wif de suffix ow (ex. pentanow, pentenow, etc.)

^ abForbes RJ (1948). A short history of de art of distiwwation. Briww. p. 89. ISBN9004006176.

^ abHaw SG (2006). "Wine, women and poison". Marco Powo in China. Routwedge. pp. 147–148. ISBN978-1-134-27542-7. Retrieved 10 Juwy 2016. The earwiest possibwe period seems to be de Eastern Han dynasty... de most wikewy period for de beginning of true distiwwation of spirits for drinking in China is during de Jin and Soudern Song dynasties